Various types of electronic devices are known for which an electrical and mechanical connection must be established between a wire or other flexible conductor and an electronic component. For example, there are numerous classes of automatic, body-implantable medical device systems, such as cardiac pacemakers and defibrillators, neural stimulators, and the like, for which it is commonly necessary to establish an electrical and mechanical coupling between an insulated conductive lead and an electronic component of the system. In a typical implantable pacemaker system, one or more pacing and sensing leads are coupled at their proximal ends to a hermetically enclosed pulse generator and have their distal ends disposed in or around the patient's heart. The leads function to conduct electrical cardiac signals to sensing circuitry within the hermetic enclosure, and to convey stimulating pulses from the pulse generator to the patient's heart.
There are particularly stringent design criteria with regard to the mechanical and electrical properties of the connection between a lead and a body-implantable device. An implantable device's lead connection is preferably highly reliable, both from a mechanical and from an electrical point of view, due to the potentially serious medical implications of either mechanical or electrical failure of the lead connection. Also, any physical structure used to implement an implantable device lead connection must be biologically inert (i.e., biocompatible), and is preferably small and light-weight.
In addition, a lead connection should be capable of withstanding repeated flexing of the lead with respect to the-device itself. This consideration is one reason that implantable leads are often implemented as a coiled conductor within an elongate insulative sleeve of silicone rubber, polyurethane or the like. Such a coiled conductor configuration has been shown in the prior art to have desirable fatigue resistant characteristics. Also, a lead connection should be strong enough to resist unintended disconnection due to the various forces that may be exerted upon it throughout the time it is implanted in the human body. At the same time, however, the delicate surgical process associated with implantation of such devices makes it desirable that the lead connection be relatively simple to effectuate in the surgical environment.